1. Long-distance wireless transmission (up to 500 meters in open area, 10kbps baud rate). 2. Operating frequency range: 433 - 458.5MHz, up to 255 communication channels. Maximum 100mW (20dBm) transmit power (10 levels adjustable). 3. Built-in MCU, serial port interface for communication with external devices. Sends up to 31 bytes at a time. 4. Supports one-to-one and one-to-many transparent transmission via ID settings. Changing the serial port baud rate automatically adjusts the wireless data transmission rate (10kbps to 100kbps). 5. Features a three-minute configuration window after power-on. During this time, the module can enter AT command mode by sending 'AT+ENABLE=1' for parameter settings. After three minutes, AT mode is no longer accessible and only data transmission is allowed. Product Name: VHF/UHF Radio Modem RS485 Wireless Transceiver 20dBm 433MHz Transmitter and Receiver Working Voltage: 4.5V - 5.5V Interface: RS485 (5V GND A+ B-) Frequency: 433MHz Transmit Power: -40dBm to +20dBm Receiver Sensitivity: -114dBm Operating Temperature: -25°C to +75°C Transparent Transmission Baud Rates: 1200, 2400, 4800, 9600 (default), 19200 Open Ground Transmission Distance: 500M Dimensions (without antenna): 74 x 24 x 16mm Usage Instructions: - For 2 pcs: Module 1 and Module 2 can send data to each other. - For 3 or more pcs: One module acts as master, others as slaves. Operates similarly to a wired RS485 bus. The master sends data and all slaves receive. Any slave can transmit data back to the master and other slaves. Only one device (master or slave) can transmit at a time. Applications: IP PTZ Camera Modbus temperature sensor LED Controller RS485 Relay Remote control and measurement systems Wireless meter reading Home automation Smart metering Access control Color: Blue Material: Plastic + Metal Package Contents: 2 x 433M-458M VHF/UHF Radio Modem RS485 Transceiver (With Shell) Note: Other items not included. Note: Lighting and display differences may cause slight color variation between image and actual item. Measurement allows for an error of +/- 1-3cm.